Present randomized, controlled, double-blind trial investigates the efficacy and safety of early (<24 h) intravenous paracetamol therapy for both the early closure of the ductus and pain medication in very small premature infants. This phase 2 drug study focuses on the efficacy and safety of short-term use. The pharmacokinetics and pharmacodynamics of paracetamol, as well as the long-term effects, are studied.